Since we know lift isn't generated by the shape of the airfoil in itself, as is erroneously taught in schools (do a search), why is the airfoil design basically universal in all wing designs?

Is it simply a matter of efficiency? That's the best shape to reduce drag?

LiveOnAPlane

01-17-2006, 04:38 PM

Just a clarification request:

I thought that the airfoil shape did generate some lift, just was not the prime mover. (Since planes can obviously fly upside down)

If this is so, then the lift would help in reducing the needed takeoff airspeed as well as the landing speed.

Not an aeronautical engineer, and I'm not saying the above is true, I just thought there was some benefit from this.

David Simmons

01-17-2006, 05:16 PM

Since we know lift isn't generated by the shape of the airfoil in itself, as is erroneously taught in schools (do a search), why is the airfoil design basically universal in all wing designs?

Is it simply a matter of efficiency? That's the best shape to reduce drag?Wing profiles can favor high lift with drag being a secondary consideration. Such a wing might suit a crop duster who needs to get in and out of tight spaces and who makes only short flights. Or it might feature a high lift-drag ratio over a wide range of angles of attack which might suit someone who operates with widely varying loads and flight condition. Or it might favor an exceptionally low landing speed.

The factor is efficiency as applied to the particular application of the wing. For long range transport, for example, you would want best efficiency in high altitude, level flight since that is where the wing spends most of its time.